1. Field of the Invention
The present invention relates generally to methods and systems for displaying information using computers, and, more particularly, presenting information contained in electronic spreadsheets and databases in tabular form.
2. Description of the Related Art
Spreadsheet and database applications allow users to view and manipulate tabular data, i.e., information organized into rows and columns. Often, the tabular data is too large to fit on a display screen. Existing applications address this problem by providing users with the ability to scroll information both vertically and horizontally. In a windowing desktop environment, such as SAP R/3®, Microsoft Windows® and the like, the problem of fitting information on the screen is exacerbated, because a plurality of windows can appear on the screen simultaneously, and each window may be significantly smaller than the display screen. Furthermore, users of most windowing desktop environments may interactively or dynamically change the size of a window at any time, which may reduce the available space for displaying tabular data.
Several existing systems attempt to overcome the problems encountered when using tables that are wider than the window space available to display them. One prior art method, chiefly implemented in database applications rather than spreadsheet applications, displays records selected for viewing or editing in a separate window or form. The disadvantage of this method is that only one record at a time may be viewed or edited in its entirety, and the viewing or editing window may obscure all or part of the window that displays tabular data in rows and columns.
Another prior art method, taught in U.S. Pat. No. 5,317,306, allows the user to determine which columns are most important to him or her, and to designate those columns as “sticky.” When a table contains more columns of information than can be displayed simultaneously, the user must scroll horizontally to view an entire row. The “sticky” columns remain in the display window when the user enters a command for horizontal scrolling. A similar prior art method is used in Microsoft Corporation's Excel spreadsheet application, in which a user may select a row, column, or cell, and choose to “freeze panes,” which splits the window, thereby causing all rows and columns above and to the left of the selected position to remain frozen in place while the rest of the display remains responsive to scrolling commands. In the prior art, a user also may make additional room in the window by designating a row or column as hidden, which suppresses its display until said row or column is unhidden by a user command.
Still another prior art method is disclosed in U.S. Pat. No. 5,621,876, which teaches a method for increasing the number of columns in the display by adding an additional column when the user selects an “increase activator” button. This method makes the window larger, if the additional column will fit on the display screen. Otherwise, it makes the other columns narrower to accommodate the additional column.
Further, U.S. Pat. No. 6,313,848 shows a method of viewing wide tables with reduced need for horizontal scrolling. The method includes the steps of determining the width of each column, determining the height of each row, and determining the dynamic height and width of the workspace available for the display of tabular data within said window and dividing the tabular data into table segments, each table segment comprising one or more columns of said tabular data.
Additional problems are encountered when displaying tabular data that is time variant. For such data, no intuitive display format has been found in the prior art.
It is therefore an object of the present invention to provide improved methods and computer systems for displaying tabular data which enable generation of an intuitive and user friendly display for time variant data.